1. Field of Invention
The present invention relates to a device and method for electricity switching, and more particularly, to a power switch device and method for a cluster computer.
2. Related Art
Stable power source is one of the most significant considerations to a computer system, especially to those applied to the field of high performance computing (HPC). Currently, to provide electricity steadily and avoid unexpected shutdown, a super computer with hundreds of nodes utilizes a large UPS (uninterrupted power system, UPS) as an external AC-to-AC power supply system. However, the external UPS is not capable of solving any power supply problems happening inside the computer system.
Except the external power supply system, an internal AC (alternating current)-to-DC (direct current) RPS (redundant power system) also keeps the computer system operating without interruptions. The primary features of a RPS are at-least-two power suppliers and hot-swap support. Therefore, when any of the operating power suppliers is failed or disconnected, the computer system will remain operative; which means each of the power suppliers in a RPS has to be capable of independently supplying all the electricity required by the computer system. Accordingly, the power supplier applied in a RPS supplies higher power, along with larger volume and high cost.
However, for low-nodes cluster computer, the internal RPS is not perfectly applicable. Please refer to FIG. 1, which illustrates a personal super computer (PSC) for personalized HPC that has applications in small-scale computing fields such as graphic processing, model analysis and research simulation. In FIG. 1 the PSC includes five mother boards; one operates as a head node 80, while the rest four are performed as compute nodes 82. A first power supplier 70 and a second power supplier 71 supply and distribute electricity through a power distribution circuit 90 to the head node 80 and the four compute nodes 82. However, PSC is a performance-oriented, density-oriented and cost-oriented product. If the first power supplier 70 and the second power supplier 71 are designed according to the system architecture of RPS, the problems of space distribution and cost will come along. Oppositely, if the RPS architecture is not utilized, the reliability will go down.
For example, each of the first and second power suppliers 70 and 71 provides 850 W, total 1700 W of electricity. Each of the compute nodes 82 needs 280 W, while the head node 80 needs 450 W; the whole system will then need 1570 W. When the first supplier 70 fails suddenly, the whole system will lost 850 W electricity in an extremely short time. If the whole system still shares the remaining 850 W electricity, then the power left for each node will be 170 W, which is obviously too much blow the required power for each node. That will cause the computer system an abnormal shutdown with irrecoverable data damage and serious task interruptions. At the moment, even the external UPS still provides with AC as usual, DC spare power is not available.
That proves that the power supplier in the prior art exists a contradiction between space distribution, cost control and reliability. Therefore, the issue becomes critical about how to improve the architecture of the power supply system in the prior art, providing the same power with a downsized volume and lower cost, and securing the data during the sudden power-off or abnormal shutdown duration.